The inventions herein concern the air traffic (and associated ground aircraft traffic) management for    a) hijacked aircraft;    b) aircraft in which an impaired pilot or pilots is/are no longer capable of flying the aircraft;    c) airfields used by unmanned aerial vehicles;    d) airfields not manned by an air traffic controller;    e) airfields and aircraft with capable onboard pilots wherein, for reasons discussed hereinbelow it may be desirable to have a supervisor or a computational device (also referred to as “logic device”) controlling a landing and/or takeoff; and    f) combinations of a)-e).
Emphasis is placed on the management of hijacked aircraft in which control has been taken away from the onboard pilot, as discussed in U.S. Pat. No. 6,917,863 and other referenced patents and applications. Nevertheless, it will be clear that the operating principles for other remotely controlled or controllable aircraft are parallel in nature—or identical.
One way of maximizing security for the above-referenced hijacking prevention system is to minimize the opportunity for an outside, ill-intentioned agent to gain (or attempt to gain) control over a remotely controlled aircraft. Parameters which may be minimized are:
a) the amount of information which the remotely guided aircraft can receive;
b) the total time during which remote guidance is allowed; and
c) the distance over which such information is transmitted.
Methods c) of minimizing the distance over which information is transmitted include the use of an interceptor aircraft, and the use of a high output transmitter to transmit commands and a low sensitivity receiver. These are discussed in the U.S. Pat. No. 6,917,863 and in application Ser. No. 10/919,169.
Other methods techniques for minimizing interference include the use of highly directional signal transmission, and encoding and encryption techniques, also discussed in U.S. Pat. No. 6,917,863 and in application Ser. No. 10/919,169.
Considering a) and b) above:
The theoretic extreme case is one in which there is no remote guidance whatsoever, i.e. in which the flight, from the time of button press until the time of landing, runs entirely on autopilot. The problems with such a system are:
a) inability to navigate around bad weather en-route to the secure airfield (SAF);
b) inability to make last minute corrections due to unanticipated turbulence, microbursts, wind shear or other unfavorable conditions in the vicinity of the secure airfield; and
c) the fact that the system can be defeated by hijacking multiple aircraft at around the same time and flooding the secure field with arrivals. Two aircraft attempting to land simultaneously, both with essentially identical glide paths, runway assignments and arrival times would collide.